This invention pertains to a system for filtering fluids contaminated with raw sewage from household toilets, the treatment of the filtered effluent and the eventual return of the fluid to again be used in the toilet. Specifically, the system is designed for recycling the water in a toilet for the express purpose of reducing by over 99% the consumption of water normally used to flush the toilet. It is to be understood, however, that the system can be used in any situation wherein it is desirable to remove extraneous matter in the form of solids whether noxious or not from a fluid either to enable recovery of the fluid or recovery of the extraneous matter.
The known systems for filtering have a number of disadvantages when the task involves the filtering of high concentrations of solids. One of the disadvantages is the rapid clogging of the surface of the depth filtration media, resulting in a rapid pressure drop across the filter. As the surface cake becomes more and more impervious to the passage of solids, a large portion of the filter media below the surface is not used.
Another disadvantage is that when a filter media is selected such that the filterable particles are allowed to penetrate the filter media to greater depth as in the true depth filtration, the filtered particles of smaller size commonly pass completely through the filter bed, resulting in poor filter performance.
The main object of this invention, therefore, is to overcome these primary disadvantages. Because household toilet wastes, after being broken down by a hydraulic attrition unit, are comprised of a wide range of particle sizes and vary in consistency, a further object of this invention is to provide a non-clogging filter system that is efficient over a wide range of conditions and particle sizes, yet which will be compact enough to install in a typical single-family dwelling using only as much space as a common 40 to 50 gallon hot water tank. A further object of this invention is to provide a depth filtration system comprised of a floating bed of filter particles of relatively large media elements and a flow path intentionally developed to uniformly distribute the incoming waste water throughout the media elements while dislodging and causing to settle the contaminants collected by the previous filtration cycle. Still a further object is to provide a highly efficient and reliable system capable of being manufactured at a cost that a house owner could rapidly recover when compared to the increasing costs of water consumption, sewers and septic tank maintenance.
Other characteristics of the invention will become evident from the description with reference to the accompanying drawings.